JPH0293847A - Memory test system at time of initial diagnosis - Google Patents

Abstract

PURPOSE:To discover the defect of a hardware as well by executing a memory access by both a real mode by a LIM system and a protect mode. CONSTITUTION:Means 1 and 2 to write data for the capacity of a memory 3 by the LIM system, which is a first mode to be obtained by a processor 1, and the means 1 to move to the second mode after the writing is finished, to read data by the protect mode and to compare the data with the above mentioned writing data are provided. Further, the means 1 to interrupt the diagnosis of the memory 3 when dissidence is generated and to inform address data of an external part, and a means to execute Write / Read / Compare by the second mode in the case of the dissidence and to execute the judgement of causes according to a compared result are provided. Thus, the defect of the memory 3 itself is discovered and since the memory access is executed by the two modes which are obtained by the processor, the defect of the hard ware can be discovered as well.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a memory test method at the time of initial diagnosis that is particularly suitable for use in personal computers.

(Prior Art) Conventionally, the memory area that can be used under an operating system that has become a standard in the field of personal computers is 1M or less. Using a method called LIM, it was possible to access memory areas of 1M or more.

LIM is a type of extended memory method. Nowadays, as systems with large capacities are emerging, the system checks the memory size using an initial diagnostic program when the power is turned on.
WrHe/Read/co for the memory size
mpare (Write/Lee P/Conia) is performed to check if the memory can be used normally, but as mentioned above, if the memory area is 1M or more, if it is used under Shibei 0S, memory access must be performed using the LIM method. Depending on the application software, you may need to use Protect Mode directly.
Yo, Ri1. Two copies are required when accessing M or more,
The initial diagnostic program uses two access methods (LIM
access method and protected mode access method).

The present invention has been made in view of the above circumstances, and it is possible to perform a memory test of IMB or higher in the initial diagnosis program.
It is an object of the present invention to provide a memory test method at the time of initial diagnosis, which can detect hardware defects by performing both IM access and protected mode access.

[Structure of the Invention] (Means and Effects for Solving the Problems) The present invention checks the memory size using an initial diagnostic program when the power is turned on, and writes data to the memory corresponding to the size.
/ Read / Compare, there is a means for writing data equivalent to the memory capacity in the first mode of the processor, and a means for moving to the cylinder 2 mode after the writing is completed, reading the data, and rewriting the previously written data. A means for comparing the memory diagnosis with the address data when a discrepancy occurs, and a means for notifying the address/data to the outside when a discrepancy occurs, and a means for performing a Wrre /Read /Co
It consists of means for performing mpare and determining the cause according to the results.

In the above configuration, first, the first mode P that the processor has is
(Write data to a memory of 1M or more in LIM real mode) (Write) l, Read data in the second mode (protected mode). Data collection 1' (R
ead) data, and if different data is found, create and display the address and data. If the data do not match here, do not use the first mode and use the protected mode to
Perform ad/com pare.

If the memory access KM cause in the first mode does not match again if the memory access is performed normally, it can be determined that the memory is defective.

This has the effect of not only discovering defects in the memory itself, but also discovering defects in hardware by performing memory access using the two memory processors.

(Example) Hereinafter, an example of the present invention will be described in detail using the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, 1 is a CPU, which reads and executes an initial diagnosis program stored in a ROM 4. 2 is LI
The M control unit is for the CPUZ to access a memory of 1M or more in real time. 3 is memory, data paste used in various applications-P
Used for (Read/Write). 4 is a ROM which stores an initial diagnosis program. 5
is a CRT display, and displays the address and data if an error occurs during the memory test.

FIG. 2 is a flowchart showing the operation of the embodiment of the present invention.
A memory test processing procedure for MB or more is shown. The symbol ■ is a step to write to memory.
Write data to a memory of 1M or more using the M method. Symbol ■ is a step for comparing data, in which data written in the LIM method and data read in the protect mode are compared. Symbol ■ indicates a step to be executed when the comparison result does not match, and an error address and data are created and displayed on the CRT display 5. Sign■
This is the step of writing to memory, and data is written to a memory size of jDIM or more in protected mode. The symbol ■ is a step to compare data, and the data written in protect mode is
Lead with.

Hereinafter, the operation of the embodiment of the present invention will be explained in detail. First, after powering on the system, the CPUJ is 1MB
Perform the above memory size check and confirm the memory capacity. After confirmation, IM in real mode using LIM method
- Write data up to the memory size, and when the memory size is completed, move to protect mode 0, read data from LM, PL, and compare with the written data. If the read and comparison are successfully performed up to the memory size, the memory diagnosis ends, but if a mismatch occurs between the write data and the read data during the process, the address where the memory mismatch occurred is checked. Data is created and displayed on the CRT display 5.

After displaying, write with only protect shade
/Read/Compare, and if the write/read (Write/Rend) is performed normally, LI
It is determined that the cause is memory access using the M method,
If a mismatch occurs again, it can be determined that the memory is defective. By performing this process in this way, 1M
By diagnosing B or higher memory and accessing using the LIM method, it is also possible to diagnose bar Pware.

〔Effect of the invention〕

As described in detail above, according to the present invention, in the initial diagnosis of memory of IMB or higher, it is possible to discover a defect in the memory itself and perform memory access in real mode and protected mode Y using the LIM method. It has the advantage of being able to detect hardware defects.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a flow chart showing the operation of the embodiment of the present invention. 1... CPU1 J... LIM control unit, 3... Memory, 4... ROM, 5... CRT display.

Claims (1)

[Claims] In a computer system that checks the memory size when the power is turned on and tests the memory of the size, means for writing data of the memory size in a first mode of the processor, and after the writing is completed. , a means for shifting to a second mode, reading the data and comparing it with the written data, and a means for interrupting the test when a discrepancy occurs, generating the address data and notifying the outside. , if a discrepancy occurs, the second
A memory test method at the time of initial diagnosis, characterized by comprising means for performing a memory test in the mode and determining the cause based on the result.